Process for the production of high-purity bisphenol A

• US 5,300,700 A
• Filed: 04/20/1993
• Issued: 04/05/1994
• Est. Priority Date: 04/28/1992
• Status: Expired due to Term

• Current Assignee: Bayer AG
• Original Assignee: Bayer AG
• Inventors: Eitel, Alfred, Wirges, Hans-Peter, Malamet, Georg, Wulff, Claus
• Primary Examiner(s): LONE, WERREN
• Application Number:
  US08/048,219
• Time in Patent Office: 350 Days
• Field of Search: 568/727, 568/724, 568/722, 568/723, 568/728
• US Class Current: 568/724
• CPC Class Codes: C07C 37/84 by crystallisation
• CPC Class Codes: C07C 39/16 Bis-(hydroxyphenyl) alkanes; Tris-(hydroxyphenyl)alkanes

Abstract

The invention relates to a special process for the production of high-purity bisphenol A from acetone and phenol in the presence of acidic catalysts.

Claims

1. A process for purifying bisphenol A from reaction solutions prepared by reacting phenol with acetone in the presence of acid catalysts, which comprises cooling the reaction solution to crystallize bisphenol into its 1:

1 adduct with phenol, separating the adduct from the phenol mother liquor, adding to the separated adduct phenol in such quantity that the total phenol content is at least 40% by weight, purifying the resulting mixture by fractional melt crystallization, and separating the resulting adduct by distillation into bisphenol A and phenol.

2. The process of claim 1 wherein the phenol mother liquor is returned to the process reaction of phenol with acetone.

3. The process of claim 1, wherein the reaction solution is cooled to a temperature of about 45 degrees C.

4. The process of claim 1, wherein the melt crystallization is carried out in an inert gas atmosphere.

5. The process of claim 1, wherein the phenol separated by distillation is returned to the process reaction of phenol with acetone.

6. The process of claim 1, wherein the purified bisphenol A is greater than 99% by weight pure.

7. The process of claim 1, wherein the purified bisphenol A is greater than 99.9% by weight pure.

8. The process of claim 1, wherein melt crystallization is carried out at a temperature of 100 to 120 degrees C.